Correction: Sex differences in pulmonary function parameters among Indigenous Australians with and without chronic airway disease.

[This corrects the article DOI: 10.1371/journal.pone.0263744.].

Chest computed tomography findings among adult Aboriginal Australians with bronchiectasis in the Top End Northern Territory of Australia.

INTRODUCTION: There is limited evidence in the literature illustrating chest computed tomography (CT) characteristics among adult Aboriginal Australians with bronchiectasis. This retrospective study evaluates the radiological characteristics of bronchiectasis in Aboriginal Australians residing in the Top End, Northern Territory of Australia. METHODS: Patients aged >18 years with chest CT-confirmed bronchiectasis between 2011 and 2020 were included. Demographics and relevant clinical parameters were collected. Alongside confirming bronchiectasis, chest CT reports were assessed for (i) lobar location (ii) unilateral or bilateral involvement and (iii) bronchiectasis type when available. RESULTS: A total of 459 patients were identified with chest CT-confirmed bronchiectasis, with a median age of 47 years, and 55% were females. Bronchiectasis was predominantly recorded in the left lower lobe (LLL) (73%), followed by the right lower lobe (RLL) (62%) and the left upper lobe (LUL) was least common (22%). Females recorded the right middle lobe (RML) affected significantly more often than males (50 vs. 34%, P = 0.012). Bilateral involvement was common (74%), with the strongest pairwise correlation associated between the right upper lobe (RUL) and LUL (P < 0.001). Cylindrical (50%) and cystic (28%) types were most common. The RML and LLL showed positive correlation with cylindrical and LUL with cystic bronchiectasis. Neither lobar location nor bronchiectasis type showed any significant association with lung function parameters other than RML, Lingula and LUL involvement being associated with better percent predicted values of diffusing capacity for carbon monoxide. There were no significant associations between sputum culture and type or lobar locations of bronchiectasis except for non-Aspergillus fungus culture prevalence was higher with cystic or cylindrical types. CONCLUSION: The results of this study may be an avenue to develop CT bronchiectasis severity scale in the future specific for Aboriginal Australians.

Sex differences in pulmonary function parameters among Indigenous Australians with and without chronic airway disease.

BACKGROUND: Studies assessing normative values and sex differences in pulmonary function test parameters (PFTPs) among Indigenous populations are sparse. METHODS: PFTPs were compared between male and female Indigenous Australian adults with and without chest radiologically proven chronic airway diseases (CADs). RESULTS: 485 adults (56% were female) with no significant difference in age, body mass index or smoking status between sexes were included. Females displayed a higher prevalence of radiology without CADs compared to males (66 vs. 52%, respectively). Among patients without CADs, after adjustment for age, stature and smoking, males displayed significantly higher absolute values of Forced Vital Capacity (FVC) (mean difference, 0.41L (0.21,0.62), p<0.001) and Forced Expiratory Volume in one second (FEV1) (mean difference 0.27L (0.07,0.47), p<0.001), with no significant difference in FEV1/FVC ratio (mean difference -0.02 (-0.06, 0.02), p = 0.174). Male and female patients with radiologically proven CADs demonstrated lower FEV1/FVC values. However, compared to females, males showed significantly greater reductions in pre- [-0.53 (-0.74, -0.32) vs. -0.29 (-0.42, -0.16), p = 0.045] and post- [-0.51 (-0.72, -0.3) vs. -0.27 (-0.39, -0.14), p = 0.049] bronchodilator FEV1. CONCLUSIONS: There are significant sex differences in the PFTPs among Indigenous Australians. Recognising these differences may be of value in the accurate diagnosis, management, monitoring and prognostication of CADs in this population.

Chest computed tomography findings among adult Indigenous Australians in the Northern Territory of Australia.

INTRODUCTION: There is sparse evidence in the literature in relation to the chest computed tomography (CT) findings among adult Indigenous Australians with chronic respiratory conditions. METHODS: In this retrospective study, patients who underwent chest CT between 2012 and 2020 among those referred to undergo lung function tests (spirometry) were assessed for the prevalence of abnormal chest CT radiological findings. RESULTS: Of the 402 patients (59% female) included in this study, 331 (82%) had an abnormality identified on chest CT. Most abnormalities occurred alongside one (25%) or multiple (46%) other CT abnormalities. Airway disease ((AD) (including, emphysema, airway wall thickening and small airway disease) (35%), atelectasis: segmental or lobar collapse (27%), inflammatory opacities (24%) and bronchiectasis (23%) were the most common findings. AD and bronchiectasis were also the most common concurrent abnormalities in 40-50%. Other CT abnormalities noted in isolation or in combination with other CT findings were lung nodules (19%), lymph node enlargement (17%), consolidation or mass (17%), followed by lung cysts, ground-glass opacity, lung parenchymal architectural distortion, cavitating lung lesions and chronic pleural effusion were observed in ≤10%. Predictive models for odds of abnormality and outcomes showed age, smoking and underweight were associated with AD, and male sex and very remote residence were associated with bronchiectasis. CONCLUSION: This study has illustrated that Indigenous Australian adults have a high prevalence of multiple chest CT abnormalities that may impose unprecedented diagnostic and therapeutic challenges in this population. Further studies are warranted to determine the long-term implications and prognostic significance of the CT findings as demonstrated in this study.

Critical analysis of spirometric patterns in correlation to chest computed tomography among adult Indigenous Australians with chronic airway diseases.

Background: There is sparse literature evidence in the spirometric patterns of adult Indigenous Australians with and without chest computed tomography (CT)-proven chronic airway diseases (CADs).Methods: Participants spirometry testing graded as acceptable for quality and had a chest CT scan showing radiographic evidence of CADs were included for analysis.Results: Of the 1350 spirometric tests performed between 2012 and 2020, a total of 212 patients with a mean age of 53 years and 54% females were eligible to be included. One-third (30%) had normal chest CT (without CADs), 35% had predominant COPD, 19% bronchiectasis and 16% combined COPD and bronchiectasis. Percentage predicted values for forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) both pre- and post- bronchodilator were significantly reduced for all participants - FVC: CT-normal 64%, 65%; COPD 58%, 62%; bronchiectasis 54%, 54%; combined COPD and bronchiectasis 50%, 53%. FEV1: CT-normal 62%, 65%; COPD 46%, 49%; bronchiectasis 48%,51%; combined COPD and bronchiectasis 36%,40%. FEV1/FVC was only reduced for CT abnormality patients - CT-normal 96%,98%; COPD 77%,77%; bronchiectasis 87%,89%; combined COPD and bronchiectasis 71%,72%.Conclusions: Restrictive spirometric pattern is common and an obstructive pattern with COPD, in isolation or when COPD coexists with bronchiectasis.

Lung function parameters among Australian Aboriginal 'apparently healthy' adults: an Australian Caucasian and Global Lung Function Initiative (GLI-2012) various ethnic norms comparative study.

Background: There is sparse literature evidence evaluating the applicability of the GLI-2012 spirometric norms for Australian Aboriginal adults.Methods: Lung function parameters (LFPs) were compared between Australian Aboriginal and Australian Caucasians, and the fit of Australian Aboriginals LFPs with various ethnic GLI equations was tested.Results: Of 1350 and 5634 Pulmonary function tests (PFTs) in Australian Aboriginal and Australian Caucasian adults, 153 and 208 PFTs matched for anthropometrics and normal chest radiology, respectively. Absolute FVC and FEV1 values were 20% lower in Australian Aboriginals compared to Australian Caucasians. Differences remained significant after accounting for age, sex, height, weight and smoking status in multivariate regression (FVC -0.84 L (-0.98, -0.71), FEV1 - 0.72 L (-0.84, -0.59), but with nearly preserved FEV1/FVC. GLI-2012 transformation resulted in z-scores significantly below zero for each of FVC, FEV1 and FEV1/FVC with z-scores ranging from -4.52 (-4.87, -4.16) for North East Asian FVC transformation for males, to -0.34 (-0.73, 0.05) for Black FVC transformation for females.Conclusions: Australian Aboriginal adults had 20% lower values for FVC and FEV1 but nearly preserved absolute FEV1/FVC in comparison to Australian Caucasians. The GLI-2012 spirometric norms do not appear to fit for Australian Aboriginal adults regardless of which ethnicity options selected, including 'others/mixed'.